diff --git a/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java b/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java
index 593bc1ea820..a322d5741bc 100644
--- a/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java
+++ b/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java
@@ -606,6 +606,7 @@ public void createVolume(CreateVolumeSpec v, ReturnValueCompletion<VolumeStats>
 
         if (v.isEncrypted()) {
             try {
+                v.setSize(alignSize(v.getSize()));
                 getVolumeEncryptionExtension().createEncryptedEmptyVolume(encryptionBackend(), v, comp);
             } catch (OperationFailureException e) {
                 comp.fail(e.getErrorCode());
@@ -657,7 +658,9 @@ public void trashVolume(String installPath, Completion comp) {
     public void cloneVolume(String srcInstallPath, CreateVolumeSpec dst, ReturnValueCompletion<VolumeStats> comp) {
         if (dst.isEncrypted()) {
             try {
-                getVolumeEncryptionExtension().cloneEncryptedVolumeFromImage(encryptionBackend(), srcInstallPath, dst, comp);
+                ZbsVolumeEncryptionBackend backend = encryptionBackend();
+                dst.setSize(alignSize(dst.getSize()));
+                getVolumeEncryptionExtension().cloneEncryptedVolumeFromImage(backend, srcInstallPath, dst, comp);
             } catch (OperationFailureException e) {
                 comp.fail(e.getErrorCode());
             }
@@ -750,7 +753,9 @@ public void handle(ErrorCode errCode, Map data) {
     public void copyVolume(String srcInstallPath, CreateVolumeSpec dst, ReturnValueCompletion<VolumeStats> comp) {
         if (dst.isEncrypted()) {
             try {
-                getVolumeEncryptionExtension().copyEncryptedVolumeFromSnapshot(encryptionBackend(), srcInstallPath, dst, comp);
+                ZbsVolumeEncryptionBackend backend = encryptionBackend();
+                dst.setSize(alignSize(dst.getSize()));
+                getVolumeEncryptionExtension().copyEncryptedVolumeFromSnapshot(backend, srcInstallPath, dst, comp);
             } catch (OperationFailureException e) {
                 comp.fail(e.getErrorCode());
             }
@@ -880,7 +885,7 @@ public void expandVolume(VolumeInventory volume, long size, ReturnValueCompletio
                 comp.fail(operr("cannot find ZBS volume encryption extension"));
                 return;
             }
-            exts.get(0).resizeEncryptedVolume(self.getUuid(), volume, size, comp);
+            exts.get(0).resizeEncryptedVolume(self.getUuid(), volume, alignSize(size), comp);
             return;
         }
 
diff --git a/storage/src/main/java/org/zstack/storage/encrypt/ZbsEncryptedVolumeCloner.java b/storage/src/main/java/org/zstack/storage/encrypt/ZbsEncryptedVolumeCloner.java
index 44e69e2fc1f..c475df30815 100644
--- a/storage/src/main/java/org/zstack/storage/encrypt/ZbsEncryptedVolumeCloner.java
+++ b/storage/src/main/java/org/zstack/storage/encrypt/ZbsEncryptedVolumeCloner.java
@@ -142,15 +142,11 @@ public void fail(ErrorCode errorCode) {
     private void resolveCloneVirtualSize(ZbsVolumeEncryptionBackend backend, String srcInstallPath,
                                          String resolvedSrcInstallPath, CreateVolumeSpec dst,
                                          ReturnValueCompletion<Long> completion) {
-        if (dst.getSize() > 0) {
-            completion.success(dst.getSize());
-            return;
-        }
-
         Long dbSize = findSourceVirtualSizeInDb(backend, srcInstallPath);
         if (dbSize != null && dbSize > 0) {
-            dst.setSize(dbSize);
-            completion.success(dbSize);
+            long virtualSize = Math.max(dst.getSize(), dbSize);
+            dst.setSize(virtualSize);
+            completion.success(virtualSize);
             return;
         }
 
@@ -165,8 +161,9 @@ public void success(VolumeStats stats) {
                     return;
                 }
 
-                dst.setSize(size);
-                completion.success(size);
+                long virtualSize = Math.max(dst.getSize(), size);
+                dst.setSize(virtualSize);
+                completion.success(virtualSize);
             }
 
             @Override